The present invention relates to moving objects on a conveyor. In particular, the invention relates to a multi-level conveying apparatus and a method of moving objects on a multi-level conveyor.
Multi-level conveying systems are widely used in manufacturing facilities, such as assembly lines or the like, for treating products. One example of a well known treatment is drying painted articles. Typically, the product being mass produced is placed into a series of trays or the like, which move along the conveyor from level to level while the product is treated. In order for the particular treatment, such as drying, to be completed, the product requires a predetermined retention time in a designated space. One example of a designated space is a dryer chamber.
U.S. Pat. No. 1,881,063 discloses a multi-level conveyor apparatus which include a conveyor bounded by two elevators which advance trays through the entire conveyor from the top level sequentially to the bottom level. An additional track structure is required to return the trays to their starting position on the top level. However, the additional track structure reduces the efficiency of the multi-level conveyor by occupying space which could be used to increase the length of the conveyance path.
U.S. Pat. No. 5,466,290 discloses a multi-level conveyor which includes two sections and three elevators. Two of the elevators are located on the sides of the conveyor and and a third elevator is located in the middle between the two sections.
The carrier units are sequentially moved from the bottom level to the top level of the 1St section of the conveyor using the left and middle elevators. Then the carrier units are moved to the 2nd section via the top level directly connecting the first and the second sections. The carrier units then are moved from the top level to the bottom level of the 2nd section using the middle and right elevator this time. In Berta""s invention there are a number of limitations. For example, the side elevators are only designed to move carrier units in one direction; more specifically the left elevator moves the objects only up and the right elevator moves the objects only down. Secondly, Berta""s invention offers no control over the retention of objects on the conveyor, meaning once the objects have entered the system, they all undergo a similar treatment with no variation. Furthermore, possibility of changing the order of carriers on the conveyor might be of great importance and the Berta""s invention offers no such flexibility.
Consequently, there is a need for an improved multi-level conveyor and a method of moving objects on a multi-level conveyor, which reduces the space required for a given length of conveyance path and offers better efficiency, control and flexibility.
There are 3 key aspects to the current invention. The first aspect of this invention covers a multi-level conveying apparatus with one set of transfer means. The second aspect of this invention covers the said conveying apparatus comprising multiple sets of transfer means. The third aspect covers the method of moving objects along specified predetermined paths.
The first aspect of this invention is a conveying apparatus comprising a plurality of levels and one set of transfer means. One set of transfer means includes separate, but identical devices for vertical transfer of pallets each located in the elevators on different sides of the conveying apparatus.
The second aspect of this invention is a conveying apparatus comprising a plurality of levels and multiple sets of transfer means. Each set of transfer means includes separate, but identical devices for vertical transfer of pallets each located in the elevators on different sides of the conveying apparatus.
The third aspect of this invention is the method of moving objects, which allows for efficient, controlled and flexible movement of the pallets. Said method permits for pallets to circulate throughout the said conveying apparatus along the same or different paths in cycles numerous amounts of times or to transfer pallets from any starting point to any ending point.